MAX5811 Maxim, MAX5811 Datasheet - Page 11

• Manufacturer Part Number: MAX5811
• Description: 10-Bit / Low-Power / 2-Wire Interface / Serial / Voltage-Output DAC
• Manufacturer: Maxim

data flow reverses following the address acknowledge
by the MAX5811. The device transmits the first byte of
data, waits for the master to acknowledge, then trans-
mits the second byte. Figure 7 shows an example read
data sequence.
The MAX5811 is compatible with existing I
SCL and SDA are high-impedance inputs; SDA has an
open drain that pulls the data line low during the ninth
clock pulse. The Typical Operating Circuit shows a typ-
ical I
ports the standard I
general call address is ignored. The MAX5811 address
is compatible with the 7-bit I
only. No 10-bit address formats are supported.
Figure 7. Read Word Data Sequence
Figure 8. Powering the MAX5811 from an External Reference
2
C application. The communication protocol sup-
S
Sr
MSB
MSB
A6
D5
MSB
A6
IN
10-Bit Low Power 2-Wire Interface Serial,
MAX6030/
MAX6050
A5
D4
______________________________________________________________________________________
GND
A5
2
A4
D3
OUT
C 8-bit communications. The
A4
A3
D2
A3
2
C addressing protocol
A2
D1
A2
DATA BYTES GENERATED BY MAX5811
MAX5811
I
V
GND
2
A1
D0
DD
C Compatibility
DATA BYTES GENERATED BY MASTER DEVICE
A1
A0
2
X
OUT
C systems.
A0
LSB
R/W
LSB
= 0
X
LSB
R/W
= 1
ACK
ACK
ACK
MSB
C3
When the MAX5811 detects an address mismatch, the
serial interface disconnects the SCL signal from the
core circuitry. This minimizes digital feedthrough
caused by the SCL signal on a static output. The serial
interface reconnects the SCL signal once a valid
START condition is detected.
The MAX5811 uses the V
ence. Any power-supply noise is directly coupled to the
device output. The circuit in Figure 8 uses a precision
voltage reference to power the MAX5811, isolating the
device from any power-supply noise. Powering the
MAX5811 in such a manner greatly improves overall
performance, especially in noisy systems. The
MAX6030 (3V, 75ppm/°C) or the MAX6050 (5V,
75ppm/°C) precision voltage references are ideal
choices due to the low power requirements of the
MAX5811.
The MAX5811 2-wire digital interface is I
compatible. The two digital inputs (SCL and SDA) load
the digital input serially into the DAC. Schmitt-trigger
buffered inputs allow slow-transition interfaces such as
P
MSB
X
C2
Voltage-Output DAC
X
X
PD1
Digital Inputs and Interface Logic
Digital Feedthrough Suppression
ACK GENERATED BY
X
Applications Information
PD0
MASTER DEVICE
Powering the Device from an
X
D9
X
DD
D8
as the DAC voltage refer-
External Reference
X
D7
LSB
X
LSB
D6
ACK
2
C and SMBus
ACK
11